English
There is a canonical R-linear projection sndHom: tsze_R M → M with toFun := snd.
Русский
Существует каноническое линейное проецирование sndHom: tsze_R M → M, где toFun = snd.
LaTeX
$$$\text{sndHom} : tsze_{R} M \to_{\mathrm{linear}} M \; (\text{toFun} := \mathrm snd)$$$
Lean4
/-- The canonical `R`-linear projection `TrivSqZeroExt R M → M`. -/
@[simps apply]
def sndHom [Semiring R] [AddCommMonoid M] [Module R M] : tsze R M →ₗ[R] M :=
{ LinearMap.snd _ _ _ with toFun := snd }